package com.zx.mvc;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;


public class DispatcherServlet extends HttpServlet {


    @Override
    public void init(ServletConfig config) throws ServletException {
        //加载配置文件路径
        String path = config.getInitParameter("contentConfigLocation");
        //读取配置文件
        InputStream is = DispatcherServlet.class.getClassLoader().getResourceAsStream(path);

      HandlerMapping.load(is);


    }

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取用户请求的uri
        String uri = req.getRequestURI();
        //根据URI获取他的映射
        HandlerMapping.MVCMapping mapping = HandlerMapping.get(uri);
            if(mapping==null){
                resp.sendError(404, "映射地址不存在");
                return ;
            }

        Object obj = mapping.getObj();
            if(obj==null){
                resp.sendError(404, "映射地址不存在");
                return ;
            }
        Method method = mapping.getMethod();
        Object result=null;
        try {
            result= method.invoke(obj, req, resp);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        switch (mapping.getType()){
            case TEXT: resp.getWriter().write((String)result);
            break;

            case VIEW:
                resp.sendRedirect((String) result);
                break;
        }


    }
}
